The apparatus which comprises the present invention is primarily designed for use with plastic containers, such as those molded by injection molding procedures from polypropylene. While a variety of container types could be formed, this invention is primarily concerned with sizing halfjar molded blanks two of which will be subsequently welded together to form a completed jar or container. Battery jars can be formed in this manner, and in their construction, it is important that the battery jar be sized to hold exactly the number of plates desired for the cell and since the number of plates will vary from cell size to cell size, it is easier to mold half jar blanks with a longer side wall than is necessary for the greatest dimension needed and to thereafter trim each blank to the desired size.
While the present invention will deal primarily with the construction of battery jars and the trimming of blanks therefor, it should be understood that this apparatus can be used to trim a variety of containers to finished dimensions. In addition, it should also be understood that such containers can be made out of a variety of materials, the only necessity being that the container be constructed from a material that is severable by slicing techniques.
It is known, in the battery art, that battery jar blanks can be trimmed following molding through the use of saw type cutters. The problem with such procedures, however, is that the resulting finished edge can very likely be jagged or rough which does not lend itself to being welded to a similar edge. Also, a great deal of waste material, in the form of dust and chips, is created and the atmosphere around such sawing devices becomes contaminated with that dust. Additionally, the sawing operation creates a good deal of noise which increases the overall noise level within a plant environment. Together, these problems make working conditions somewhat less desirable than they might otherwise be without the use of saw type cutters.
Because many chips are being produced by such saw blades, it is also sometimes necessary to clean or otherwise treat the cut edge of the blank prior to welding which adds additional labor costs to the manufacturing process. Further, as saw blades become dull with use, it is difficult to maintain the accuracy of cuts and the process is also energy inefficient because of the power required not only to make the cut but the thousands of chips produced thereby.